As data rates exhibited by optical transmission systems continue to rise it is expected that data traffic rates may vary from 10 Gb/s to 1 Tb/s and above due, in part, to the demand for a variety of Internet services. To transmit this data efficiently using limited bandwith, flexible transponders exhibiting agile modulation format(s) and variable bit rates have been introduced.
It is generally known in the art that the QPSK is but one contemporary modulation format exhibiting increased transmission distance and spectral efficiency (SE). In addition to the QPSK modulation format, different polarization schemes have been applied such that polarization multiplexed (PolMux-QPSK), polarization modulated (PolMod-QPSK) and polarization switched (PolSw-QPSK) signals have been produced, which offer numerous benefits.